From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753915AbaKRLUQ (ORCPT ); Tue, 18 Nov 2014 06:20:16 -0500 Received: from mail-pd0-f171.google.com ([209.85.192.171]:49491 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751699AbaKRLUO (ORCPT ); Tue, 18 Nov 2014 06:20:14 -0500 From: "pang.xunlei" To: linux-kernel@vger.kernel.org Cc: rtc-linux@googlegroups.com, Thomas Gleixner , Alessandro Zummo , John Stultz , Arnd Bergmann , "pang.xunlei" Subject: [RFC PATCH v3 1/5] time: Provide y2038 safe do_settimeofday() replacement Date: Tue, 18 Nov 2014 19:15:16 +0800 Message-Id: <1416309320-7498-2-git-send-email-pang.xunlei@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1416309320-7498-1-git-send-email-pang.xunlei@linaro.org> References: <1416309320-7498-1-git-send-email-pang.xunlei@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel uses 32-bit signed value(time_t) for seconds elapsed 1970-01-01:00:00:00, thus it will overflow at 2038-01-19 03:14:08 on 32-bit systems. This is widely known as the y2038 problem. As part of addressing "y2038 problem" for in-kernel uses, this patch adds safe do_settimeofday64() using timespec64. After this patch, do_settimeofday() is deprecated and all its call sites will be fixed using do_settimeofday64(), after that it can be removed. Signed-off-by: pang.xunlei --- include/linux/timekeeping.h | 21 ++++++++++++++++++++- kernel/time/timekeeping.c | 19 +++++++++---------- 2 files changed, 29 insertions(+), 11 deletions(-) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 1caa6b0..071ad7e 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -10,7 +10,7 @@ extern int timekeeping_suspended; * Get and set timeofday */ extern void do_gettimeofday(struct timeval *tv); -extern int do_settimeofday(const struct timespec *tv); +extern int do_settimeofday64(const struct timespec64 *ts); extern int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz); @@ -33,6 +33,14 @@ extern int __getnstimeofday64(struct timespec64 *tv); extern void getnstimeofday64(struct timespec64 *tv); #if BITS_PER_LONG == 64 +/** + * Deprecated. Use do_settimeofday64(). + */ +static inline int do_settimeofday(const struct timespec *ts) +{ + return do_settimeofday64(ts); +} + static inline int __getnstimeofday(struct timespec *ts) { return __getnstimeofday64(ts); @@ -54,6 +62,17 @@ static inline void ktime_get_real_ts(struct timespec *ts) } #else +/** + * Deprecated. Use do_settimeofday64(). + */ +static inline int do_settimeofday(const struct timespec *ts) +{ + struct timespec64 ts64; + + ts64 = timespec_to_timespec64(*ts); + return do_settimeofday64(&ts64); +} + static inline int __getnstimeofday(struct timespec *ts) { struct timespec64 ts64; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index ec1791f..1d33550 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -703,18 +703,18 @@ void do_gettimeofday(struct timeval *tv) EXPORT_SYMBOL(do_gettimeofday); /** - * do_settimeofday - Sets the time of day - * @tv: pointer to the timespec variable containing the new time + * do_settimeofday64 - Sets the time of day. + * @ts: pointer to the timespec64 variable containing the new time * * Sets the time of day to the new time and update NTP and notify hrtimers */ -int do_settimeofday(const struct timespec *tv) +int do_settimeofday64(const struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; - struct timespec64 ts_delta, xt, tmp; + struct timespec64 ts_delta, xt; unsigned long flags; - if (!timespec_valid_strict(tv)) + if (!timespec64_valid_strict(ts)) return -EINVAL; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -723,13 +723,12 @@ int do_settimeofday(const struct timespec *tv) timekeeping_forward_now(tk); xt = tk_xtime(tk); - ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; - ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; + ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; + ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); - tmp = timespec_to_timespec64(*tv); - tk_set_xtime(tk, &tmp); + tk_set_xtime(tk, ts); timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); @@ -741,7 +740,7 @@ int do_settimeofday(const struct timespec *tv) return 0; } -EXPORT_SYMBOL(do_settimeofday); +EXPORT_SYMBOL(do_settimeofday64); /** * timekeeping_inject_offset - Adds or subtracts from the current time. -- 1.7.9.5